De-icing compositions are widely used in northern areas of the country, particularly in northern climates subject to heavy ice and snow conditions in the winter months. One of the inventors of the present composition has numerous patents on ice melters. See, for example, U.S. Pat. No. 7,122,127, which relates to liquid ice melters, and U.S. Pat. No. 5,683,619 which relates to solid ice melting compositions which are environmentally friendly. The disclosure of these patents is incorporated herein by reference.
A good ice melter for roads, sidewalks, parking lots, etc. is inexpensive, easy to manufacture, effective in melting snow and ice and easy to apply. The best ones also provide reduced corrosion to application equipment while also having beneficial effects to vegetation. All of these advantages in one ice melter has been a goal of the ice melting industry for some time.
Effective in melting means a product capable of melting below zero degrees F. Ease of application is also important because labor cost is one of the largest components of melting snow and ice. Liquid ice melters bring ease to the application process.
In Ossian, Inc.'s earlier U.S. Pat. No. 5,683,619 (Ossian & Steinhauser), created a product that melted below zero and could have a positive effect on vegetation. The major disadvantage to this earlier invention was the high cost to produce the product and the cost of application. It used calcium chloride and urea in a dry melter composition. When calcium chloride is manufactured for industrial use it starts out as a liquid. The water is then evaporated to form a flake or pellet. This manufacturing process uses considerable energy adding cost of manufacture for the raw material. Some of this cost could be avoided if the ice melter were liquid as a finished product.
The solid ice melter of U.S. Pat. No. 5,683,619 is advantageous in that it is an effective melter, and it brings a positive effect on vegetation. It is in content a combination of urea and calcium chloride in a solid particle format. However, in recent times it has been of interest to develop liquid ice melters. In some environments, liquid ice melters are preferred to solid ice melters in that they give better coverage, they are much quicker acting melters, and they are more economical to prepare.
The liquid ice melter of U.S. Pat. No. 7,122,127 is a product that is less expensive to manufacture, easy to use, melts below zero and can have a positive effect on vegetation. In that invention, Ossian, Inc. used liquid calcium chloride solution combined with either dry or liquid urea, in critical ratios to achieve an effective liquid ice melter that is beneficial to vegetation.
Ossian, Inc.'s most recent U.S. Pat. No. 7,473,379 the two inventors (Ossian & Behrens) chemically degraded carbohydrates and protein in sugar beet molasses (desugarized solubles) with alkali to a pH of at least 11 followed by an acid addition to lower pH to at least 10. These steps substantially and surprisingly increased melt value. The disclosure of this patent is incorporated herein, in its entirety, since the present case is an improvement on this process.
The industry has long looked for ways to either reduce or eliminate the use of salt for de-icing roadways, parking lots, sidewalks, etc. One of the more successful approaches of the past has been the use of prewetting and anti-icing. The present invention is suitable for this use.
Prewetting is the process of coating salt with different solutions as the salt is being applied to the roadway. These solutions are traditionally brines of sodium chloride, magnesium chloride and calcium chloride. In addition, various molasses agriculture by-products (e.g., Raffinate) are sometimes included with the solution. These by-products increase the viscosity of the prewet solution. The prewet process increases the melt value of the salt and reduces the bounce and scatter of dry salt when it hits the pavement. “Melt value” as used here refers to the ability to melt ice to brine at a given temperature, and it is measured by the volume of brine achieved within a specified amount of time.
Anti-icing is the process of placing the ice melter down in liquid form prior to any weather event. The concept being, it is easier to melt snow and ice from the bottom up as opposed to melting snow and ice from the top down. The concept uses less salt and is practiced by a number of State and Municipal governments. However, this method has its limits because common liquid ice melters such as solutions of calcium chloride, magnesium chloride, sodium chloride and potassium acetate all have relatively low viscosities causing run off problems. That is to say, these products do not stay in place but will instead easily penetrate into the concrete and will not have enough residual left on top of the pavement for very much melting action to occur. The problem is even more of an issue when liquid sodium chloride solution is used. The water in the solution will evaporate leaving a chalky salt residue that in some cases may dry up and blow away before a weather event even occurs.
To address this issue many have turned to a molasses type by-product derived from sugar beet (raffinate), sugar cane, corn sugars and steep water, brewers condensed solubles, distillers solubles, or mixtures thereof to increase viscosity. These by-products can provide value to the various solutions of calcium chloride, magnesium chloride, sodium chloride and potassium acetate by keeping them in place before, during and sometimes after the melting process. Adding these compositions to various solutions of ice melt chemicals helps keep them in place longer. See Patents: Bloomer U.S. Pat. Nos. 6,416,684; 6,641,753; 6,080,330; Hartley U.S. Pat. Nos. 6,299,793; 6,436,310; 6,440,325; 6,582,622; 6,596,188; 6,599,440; 6,770,217; 6,805,811; 6,827,873; 6,905,631; 7,014,789; Koefod U.S. Pat. Nos. 6,398,979; 6,800,217; Roderick U.S. Pat. No. 6,605,121.
However, all these patented products have a major limitation. The sugar by-products alone are very poor ice melters and their value potential is only to increase viscosity and act as a corrosion inhibitor. They, therefore, raise the overall costs and in most cases add little to no melting value to the liquid solution.
There has been some effort to improve the melt values of the sugar/molasses mixtures in U.S. Pat. No. 6,605,232. This patent degrades reducing sugars to a pH of 6.0 to 9.0 from steep water waste stream of agribusiness with an alkali. It requires a reducing sugar concentration of 10 to 70 parts by weight. This process is limited in availability of raw materials and in the increased melt value. In addition, it does not include the use of chloride salts. U.S. Pat. No. 6,080,330 uses raffinate but only to increase viscosity without providing any melt value enhancing pretreatment of the raffinate. Our earlier U.S. Pat. No. 7,743,379, uses treated raffinate to increase melt value. This present process improves upon U.S. Pat. No. 6,080,330.
It has now been found that by adding heat at elevated temperatures for a substantial length of time during the alkali degradation process for beet industry by-products, such as desugared sugar beet molasses, a significant melt value benefit can be achieved over our current U.S. Pat. No. 7,473,379.
A yet further benefit, can be achieve, by changing the alkali in our first U.S. Pat. No. 7,473,379 from the Group I metal sodium hydroxide to a different Group I metal, hydroxide, potassium hydroxide, one can achieve an even more significant melt value than just through use of adding heat processing during chemical degradation; in fact, this also allows production of a non-chloride ice melter for sensitive environmental areas that cannot tolerate chlorides, that still has excellent melt value properties.